In the field of semiconductors, there is a constant demand for a more sophisticated microfabrication, therefore shortening of the wavelength of light emitted from an exposure light source for photoresists is being proceeded. However, shortening of the wavelength of an emitted light will lead to reduction in exposure intensity. In order to solve this problem, a chemically amplified resist composition that utilizes an acid generator has been developed. High sensitivity can be achieved by the chemically amplified resist composition, since solubilization reactions (in the case of positive resists) and hardening reactions (in the case of negative resists) are accelerated as a result of an acid generated from an acid generator by light irradiation acting as a catalyst. As examples of such acid generators, triphenylsulfonium 1-adamantylmethoxycarbonyldifluoromethane sulfonate and the like are known (e.g., Example in Japanese Laid-Open Patent Publication No. 2004-4561).